Thread controller for sewing machines



Oct. 25, 1932. V v -Z ET AL 1,884,490

THREAD CONTROLLER FOR SEWING MACHINES Filed Dec. 1, 1930 2 Sheets-Sheet l gwuentoz S 5351i In M dbkomqS Oct. 25, 1932. F. F. ZEIER ET AL 1,884,490

THREAD CONTROLLER FOR SEWING MACHINES Filed Dec. 1, 19 2 Sheets-Sheet 2 C9 (9 m! L1; 3 gwwntovs 6 m 2] a 44 g a J e mh m Patented Oct. 25, 1932 UNITED STATES? PATENT OFFICE IEREDERICK F. ZEIER AND CLARENCE C. SMITH, OF CHICAGO, ILLINOIS, ASSIGNORS TO UNION SPECIAL IIIACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS THREAD CONTROLLER FOR SEWING MACHINES Application filed December 1, 1930. Serial No. 499,335.

. across the controller in a plane at right angles to the axis of rotation of the controller.

An object of the invention is to provide a thread controller which includes a rotating thread engaging element that is very light in weight, and which has a thread engaging surface of sufficient extent to take up and give up the thread for each stitch formation.

A further object of the invention is to provide a thread controlling element of the above type wherein the thread engaging surface is formed of sheet metal so disposed as to form a hollow lIlteIlOl.

A still further ob]ect of the invention is to "provide a thread controlling element of the above type wherein the sheet metal part forming the thread engaging surface is supported by spaced disks and transverse extending members connecting the disks so that said sheet metal part will maintain the shaping which is given thereto for obtaining.

the desired control of the thread.

In the draw1ngs:- Figure 1 is a plan view showing a portion of a sewing machine embodying the inveni tion. 7 e t Fig. 2 is a view showing the thread carrying looper at the end of a work arrnwith which the thread controller may be associated.

Fig. 3 is a sectional view through the rotating thread controlling .element with the parts positioned so that the threadis taken up and is about to be castofi from the thread engaging surface.

Fig. 4: is a view similar to Fig. 3 but showing the thread cast from the thread engaging surface so as to give slack thereto.

Fig. '5 is a view similar to Fig. 3 but showing the thread as again taken up bythe rotatingthread cont-rolling element.

Fig. '6 is an enlarged sectional view showing the manner of attaching the ends of the shee metal band forming the thread engaging surface.

The invention is directed to a thread con' trolling mechanism for sewing machines, and

more particularly to a thread controlling mechanism wherein the thread or threads are directed into engagement with a rotating thread controlling element in a direction at right angles to the axis of rotation of said element. In the application filed by Norman V. Christensen, Charles F. Rubel and Frederick F.Zeier on August 2, 1928, Serial No. 297,059, there is shown, described and claimed a thread controlling mechanism of the above character on which the present invention is an improvement.

The present invention is directed particularly to the construction of the rotating thread controlling .element. The present thread controlling element consists of two spaced disks, one of which is fixed to a rotating shaft. The two disks are rigidly connected by crossmembers which are attached to both disks. Between the two disks is the thread engaging element which is in the form of a sheet metal band. This band is attached to these transverse or cross members and is clamped thereby between the disks so as to retain the desired shape given to the band. The band is formed with a radially projecting portion whichis adapted to engage. the thread passing between two thread guides and deflect said thread so as to pull on the thread. Associated with this band are cast ofis which at a certain time in the rotation of the controlling element cast the thread or threads off from their respective thread engaging surfaces. The band may be properly shaped as to take up and give up thread to suit the requirements of the thread controller.

The invention will possibly be better understood by a more detailed description of the illustrated form contained in the drawings. As shown the invention is applied to a sewingmachine having an upper rotating shaft 1. The thread controlling element is mounted on this shaft, and is constructed for controlling three separate threads. The threads are indicated at a, b and 0 in the drawings. The threads are led from the supply through suitable tensions 2, 3 and 4 respectively, and thence through thread guides carried by an arm 5. From this point the threads extend across the thread controller which consists of two spaced disks 6 and 7 and a thread engaging member 8 located between the disks. The threads after leaving the rotating thread controlling element are led through eyes 9, 10 and 11 respectively formed in an arm 12. It will be noted that these threads as they cross the thread controlling element pass in lines or planes which are at right angles to the axis of the shaft 1 supporting the thread controlling element. If the thread controller is used in connection with a looper mechanism there is a thread for each looper. and the three threads will be independently and simultaneously acted upon by the thread controller.

In Fig.2 of the drawings there is shown one of a series of needles 13. Cooperating with each needle is a looper 14 mounted on a carrier 15 which is fixed to a shaft 16 in the work arm. In order to aid in the stitch formation the looper thread should be taken up on the retracting movement of the looper so as to maintain the thread between the eye of the looper and the previous stitch relatively taut and thus insures that the needle will pass between the looper thread and the body of the looper with which it is associated. After the needle point is well past the looper thread then it is important that the thread be given up quickly to the looper as the looper thread is held by the needle while the looper is retracting. It is also important that the thread of the looper be taken up as the looper moves forward to enter the needle thread loop so as to prevent slack forming in front of the looper and buckling and thus forcing the needle thread loop to one side and produce a skipping 0f the stitches. It is also essential that the thread be given up to the looper gradually after the point thereof is well into the needle thread loop. There are therefore two taking-up and giving-up actions that are necessary in a thread controller for a thread carrying looper.

The thread controlling member 8 located between the disks 6 and 7 is formed from a sheet metal strip or band. Extending across from one disk to the other is a cross member or strut 17. This member has a fiat face 18 and an opening therethrough through which a bolt 19 is passed. The bolt is threaded into one of the disks, and has a head bearing against the other disk so that the two disks are clamped against the ends of this cross member or strut 17 The end 20 of the thread engaging member 8 extends along this face 18 of the cross member 17 and is'then bent substantially at right angles and extends around a sleeve 21 carried by a bolt 22 which is likewise threaded into one of the disks, and has a head bearing against the other disk. This forms a straight portion 8 in the metal strip which is a portion of the thread engaging surface thereof. The strip is bent about this sleeve 21, thus forming a curved portion 8". The metal strip forming this thread engaging surface is of sufficient thickness and strength to retain its shaping. It is shaped so as to provide a relatively straight portion 8 leading to a curved portion 8 and thence to a straight portion 8. This straight portion 8 leads into a curved portion 8'. At the point 8 the strip is bent inwardly so as to provide a portion 8 which is substantially parallel with the portion indicated at 20. There is a plate 22 placed between the end portions and a clamping bolt 23 clamps the end 8 against the outer face of the plate, the plate against the end 20 of the strip, and the strip against the strut or cross member 17. There is a cross member 24 in the form of a bolt which is threaded into one disk and has a head overlying the other disk, and this bolt lies close to the inner face of the section 8 of the strip.

The plate 22.is provided with parallel recesses 22, 22 and 22. This forms three projecting portions in the strip, each of which has an incline face 25. The thread control ling element rotates in the direction of the arrow in Fig. 3. When the parts are positioned as shown in this figure the curved portion 8 contacting with the thread a between the thread guiding eye in the arm 5 and the thread guiding eye in the arm 12 will deflect the thread and draw on the thread thus taking up the thread. At this time the looper is on its backward movement and has reached the position where the point of the needle is well down into the thread triangle therefor. The incline face 25 on the plate 22 is moving into contact with the thread a and is crowding it along the thread engaging face so that it will be stripped therefrom into the curve or recess 22'. In Fig. 4 of the drawings the thread is shown as stripped from the thread engaging face 8 into the curve or recess formed in the plate and in the strip so that slack is given to the thread. As the controller continues to rotate further slack will be given to the looper, and as the looper begins its forward movement then the thread is taken up by the controller turning to the position shown in Fig. 5. At this time the pointof the looper is well into the needle thread loop, and further rotation of the thread controlling element will give up thread to the looper permitting it to move on to the end of its stroke. It will be noted therefore that the curved portion 8 of the thread controlling element engages and pulls on the thread and then the thread is dropped therefrom so that it may be given up quickly. The curved face 8 engages the thread and takes up on the thread gradually as the thread controlling element rotates and then gradually gives up thread to the looper.

The present invention is directed particularly to the construction of this thread controlling element which is formed from a sheet metal strip which is bent and shaped to the desired form for functioning in the manner described above. The ends of the strip are firmly clamped by the screw 23 and the plate 22 is slotted so that it may be adjusted radially of the thread controlling element for varying the set position of the inclined faces. This makes a very simple construction which can be easily made as it is very easy to bend and shape this strip into the desired form and much more easy to bend the strip into the desired form than it is to cut a solid block of the desired shape necessary to accomplish a proper control of the thread. Furthermore, when the thread engaging surface is made from a sheet metal strip the thread controlling element is hollow and is very light. This reduces to a minimum the efi'ort necessary to impart rotation to the thread controlling element.

While we have shown a thread controlling element having two separate portions thereof which operate in succession on the thread to take up and give up thread, it will be understood that the controlling element may be of any desired shape or form. The essential feature resides in the formation of the thread engaging surface from a strip of metal which can be readily shaped to the desired form, and which when formed is very light.

ld hile we have shown the thread engaging elementas formed from one continuous strip, it will also be understood that it may be otherwise formed.

It is obvious that changes in the details of the parts and the manner of securing the strip may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is 1-- 1. A thread controller for sewing machines including a thread engaging member formed of sheet metal bent so as to provide an irregular peripheral thread engaging surface and means for directing a thread across the thread engaging member in a direction at right angles to the axis of rotation thereof.

2. A thread controller for sewing machines including a rotating thread controlling element having the thread engaging surface thereof formed of sheet metal, means for supporting and rotating said thread controlling element, and means for directing a thread across said thread controlling element in a direction at right angles to the aXis of rotation thereof, said thread engaging surface being formed of sheet metal shaped so as to provide a radially projecting curved portion porting and rotating said thread controlling:

element, means for directing a thread across said thread controlling element in a direction at right a:.gles to the axis of rotation thereof, said thread engaging surface being formed of sheet metal shaped so as to provide a radially projecting curved portion for taking up and giving up thread during the rotation of said thread controlling element, said sheet metal being cut away at one side of the path of movement of the thread, and means carried by said thread engaging element for forcing the thread laterally off from said thread 11 aging surface into said cut away portion whereby said thread is quickly given up.

7 a. A thread controller for sewing machines including a thread controlling element havk ing the thread engaging surface thereof formed of sheet metal and a supporting thread directing disk at each side of said thread control ing element, cross members connecting said disks, and means for clamping the sheet metal forming the thread engaging surface to said cross members.

controller for sewing machines 5. A thread including a rotating thread controlling element having the thread engaging surface thereof formed of a strip of sheet metal, supporting and thread-directing disks at each side of said strip, cross members carried by said disks, the ends of said strip being attached to one of said cross members, said strip being shaped so as to provide a. thread engaging surface projecting radially for taking up and giving up the thread, and means for directing a thread across the thread controlling element in a direction at right angles to the axis of rotation of said thread controlling element.

6. A thread controller for sewing machines including a. rotating thread controlling element having the thread engaging surface thereof formed of a strip of sheet metal,'supporting and thread-directing disks at each side of said strip, cross members carried by said disks, said strip between the ends thereof being shaped so as to provide a thread engaging surface projecting radially for taking up and giving up the thread, means for directing av thread across the thread controlling element in a direction at right angles to the axis of rotation of said thread controlling element, said strip having a cutaway portion at one side of the path of movement of the thread, and a stripper plate clamped between the ends of said strip and having an inclined portion adapted to engage the thread and crowd it laterally off from said thread engag- 4 ing face into said cut-away portion.

7. A thread controller for sewing machines including a thread controlling element formed of sheet metal bent so as to provide an irregular peripheral thread engaging surface, means for supporting and rotating said thread controlling element, means for directing a thread across said thread controlling element in a direction at right angles to the axis of rotation thereof, said thread controlling element having a cut-away portion at one side of the path of movement of the thread and a member carried by said thread controlling element for engaging and forcing the thread laterally off from the thread engaging surface into said cut-away portion.

8. A thread controller for sewing machines including a thread controlling element formed of sheet metal bent so as to provide an irregular peripheral thread engaging surface, means for supporting and rotating said thread controlling element, means for directing a thread across said thread controlling element in a direction at right angles to the axis of rotation thereof, said thread controlling element having a cut-away portion at one side of the path of movement of the thread, a member carried by said thread controlling element for engaging and forcing the thread laterally oil from the thread engaging surface into said cut-away portion, said member for forcing the thread laterally having a thread engaging surface which is inclined downwardly toward the cut-away portion and means for adjusting said member relative to the thread engaging surface.

In testimony whereof, we affix our signatures.

FREDERICK F. ZEIER. CLARENCE C. SMITH. 

